Parabolic solar reflector troughs are used to focus the sun's rays upon a tube which runs along a focal line defined by the parabola. A liquid flowing through the tube can be heated to high temperature, for example, to about 700.degree. F. Such reflectors face upwardly and are exposed to the elements, including wind, snow, dust, soot, pollutants and rain. It is accordingly necessary that they be covered with a transparent cover which will allow the sun's rays to pass into the parabolic reflector and be reflected onto the target pipe yet will keep rain, dust, snow and the like from contacting the parabolic reflector surface and will also keep winds from blowing too strongly into the structure defining the parabola so as to prevent or minimize wind damage.
A problem which exists with many prior art parabolic reflectors is that they are both heavy, thus making their installation on roofs and the like impossible in many instances without extensive bracing of the roofs, and expensive. The problem of producing relatively light weight and inexpensive parabolic reflectors has been partially solved by utilizing a parabolic reflector which is in the nature of a tensioned parabolic sheet having a reflective surface. This type of apparatus is disclosed, for example, in U.S. Pat. Nos. 4,596,238 issued June 24, 1986 and 4,510,923 issued Apr. 16, 1985. When one utilizes a tensioned sheet type of parabolic reflector it is particularly important to prevent winds, which may reach speeds of well in excess of eighty miles per hour, from damaging the reflector.
Another problem with prior art solar reflector covers has been that they have been relatively bulky to transport and relatively difficult to assemble. This has lead to increased cost.
The present invention is directed to overcoming one or more of the problems as set forth above.